The world should abandon the Kyoto protocol on climate change and move instead to a system where each nation would have a carbon emissions quota based on population, the UK's former chief scientist has urged, in an explosive contribution to the long-running climate negotiations.

He told the Guardian: "I can't see the Kyoto protocol making any headway - there are enough blocks in place, especially from the US and China, that it is wholly unlikely that it will go on. We need to be pragmatic." He said his proposals - by which countries could take their own actions on greenhouse gases without agreeing them at an international level - offered "a far more realistic pathway than hoping countries will come together in an international agreement at a single point".

"If you say only a full [legally binding] treaty is any good, we will still be arguing about it in 20 years," he said.

King - who was born in Durban, South Africa, where the next round of climate talks will take place this December - will publish a report on Monday intended to inject new life into the long-running United Nations talks. The ultimate aim, he said, should be that by mid-century each country should have an emissions quota based on their population - probably set at around two tonnes of carbon per person - supported by a carbon trading system, by which rich countries wanting to exceed their quota could buy carbon credits from poorer nations. The average UK citizen has a carbon footprint around 4.5 times that, while the average US citizen's footprint is 10 times as large.

In order to get to that point, according to King, negotiators should accept that countries must be allowed to make their own decisions on measures to reduce emissions without the framework of an over-arching agreement.

King's views are an attack on some of the most dearly held tenets of the climate change talks. While the idea of a per capita emissions quota will appeal to some, many developing countries are insistent that the Kyoto protocol must be continued, as the only international treaty that requires rich nations to cut their greenhouse gas emissions. They, along with green campaigning groups, also want any new agreement to be a fully legally binding treaty - not a voluntary system countries can enter if they wish, and under which they can change their minds on emissions targets at any time.

But King believes these entrenched positions need to be abandoned and radical new ideas and more "realism" injected into the negotiations, if they are to be successful. He argues that moving away from the goal of a fully articulated global treaty to a system of voluntary actions, and bilateral or multilateral agreements among nations will achieve this. This would mean governments and the United Nations would have to accept some countries - perhaps including the US, Opec countries and others - might effectively opt out of the process.

A measure of the outrage that King's proposals are likely to provoke came from Chris Huhne, the UK climate secretary. He said: "Sidelining the push for a legally binding deal on curbing emissions in favour of a voluntary approach is about as useful for the climate as a chocolate tea pot. Pledges without the seriousness of a legal commitment are only a stop gap."

He said the negotiations were "already making a difference" and that a legally binding global deal was "essential in providing the legitimacy to ensure that all countries deliver the level of emissions reductions we need and providing investors with the certainty to invest in technology to make that happen".

King's report, for Oxford's Smith School of Enterprise and Environment, where he is director, shows that the 1997 Kyoto protocol had little effect on emissions outside Europe. This means that in nearly 20 years of negotiations the world has failed to produce an effective and comprehensive global agreement on emissions.

"Since 1992 [when the first talks took place], 192 nations have achieved remarkably little - despite the fact that no other single topic in the world has been given so much of policymakers' time," he said. "But in parallel, national actions and actions by business have brought about very substantial change."

By scrapping the Kyoto protocol and moving to a voluntary system whereby countries could make commitments on curbing emissions and later revise them - so-called "pledge and review" - the world could build on the progress that some countries have already made, he said.

As part of the report, King's team tracked progress on emissions around the world, producing a map showing which countries have done most. Several Latin American countries, including Brazil and Mexico, and Indonesia, Japan and Norway all emerged as "very good". The European Union was rated "good" in terms of its progress, and the US, Canada, Australia and parts of the Middle East were classed "very poor".

King's contribution was welcomed by some observers of the talks who have long argued that the deadlock can only be broken by accepting that a legally binding treaty may be out of reach and concentrating instead on concrete actions that would achieve reductions in emissions. "This report confronts the fact that a binding treaty is not going to occur in the near future, and that the pledge and review approach can bring important gains," said Paul Bledsoe, a former Bill Clinton White House official on climate change and veteran of the climate talks.

"For too long negotiators and activists have let the perfect be the enemy of the good. The motto should be start and strengthen, a method that has worked well for the Montreal protocol process. That said, pressure on major emitters to make cuts must be made in all venues, including the G20 and the major economies forums, to be fully effective."

But King's proposals are likely to be controversial for many participants, including some developing countries and green pressure groups.

"Scrapping Kyoto and waiting for something better to come along is a bit like abandoning your car by the side of the road in the hope someone will pick you up later," said Ruth Davis, chief policy adviser at Greenpeace. "The new report's authors are right to stress that global co-operation and common rules are essential, but Kyoto is the only agreement the world has made so far that moves us closer to those goals. Scrapping it would send a destructive signal to investors and undermine the green economy."

She urged governments to agree to a "second commitment period" for the protocol, to continue when the current commitments expire in 2012. "Europe's leaders can secure the future of the Kyoto later this year, by agreeing to a second commitment period," she said. "It is in their interests to do so, both to drive much-needed investment in the clean energy sector, and to begin the transition to a comprehensive global agreement over the next decade."

King's proposal of a global emissions quota based on population has its roots in the idea of "contraction and convergence", first put forward in the early 1990s, by which countries would reduce their greenhouse gas output and move towards equal emissions across the world. King said the system could be devised in such a way that it did not simply encourage population growth.